NAME

       Crypt::PRNG - Cryptographically secure random number generator

SYNOPSIS

          ### Functional interface:
          use Crypt::PRNG qw(random_bytes random_bytes_hex random_bytes_b64 random_bytes_b64u
                             random_string random_string_from rand irand);

          $octets = random_bytes(45);
          $hex_string = random_bytes_hex(45);
          $base64_string = random_bytes_b64(45);
          $base64url_string = random_bytes_b64u(45);
          $alphanumeric_string = random_string(30);
          $string = random_string_from('ACGT', 64);
          $floating_point_number_0_to_1 = rand;
          $floating_point_number_0_to_88 = rand(88);
          $unsigned_32bit_int = irand;

          ### OO interface:
          use Crypt::PRNG;

          $prng = Crypt::PRNG->new;
          #or
          $prng = Crypt::PRNG->new("RC4");
          #or
          $prng = Crypt::PRNG->new("RC4", "some data used for seeding PRNG");

          $octets = $prng->bytes(45);
          $hex_string = $prng->bytes_hex(45);
          $base64_string = $prng->bytes_b64(45);
          $base64url_string = $prng->bytes_b64u(45);
          $alphanumeric_string = $prng->string(30);
          $string = $prng->string_from('ACGT', 64);
          $floating_point_number_0_to_1 = $prng->double;
          $floating_point_number_0_to_88 = $prng->double(88);
          $unsigned_32bit_int = $prng->int32;

DESCRIPTION

       Provides an interface to the ChaCha20 based pseudo random number generator (thread-safe
       and fork-safe).

FUNCTIONS

   random_bytes
          $octets = random_bytes($length);

       Returns $length random octects.

   random_bytes_hex
          $hex_string = random_bytes_hex($length);

       Returns $length random octects encoded as hexadecimal string.

   random_bytes_b64
          $base64_string = random_bytes_b64($length);

       Returns $length random octects Base64 encoded.

   random_bytes_b64u
          $base64url_string = random_bytes_b64u($length);

       Returns $length random octects Base64 URL Safe (RFC 4648 section 5) encoded.

   random_string_from
          $string = random_string_from($range, $length);
          #e.g.
          $string = random_string_from("ABCD", 10);

       Returns a random string made of $length chars randomly chosen from $range string.

   random_string
          $alphanumeric_string = random_string($length);
          #or
          $alphanumeric_string = random_string;  # default length = 20

       Similar to random_string_from, only $range is fixed to
       'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'.

   rand
          $n = rand;
          #or
          $n = rand($limit);

       Returns a random floating point number from range "[0,1)" (if called without parameter) or
       "[0,$limit)".

   irand
          $i = irand;

       Returns a random unsigned 32bit integer - range "0 .. 0xFFFFFFFF".

METHODS

   new
          $prng = Crypt::PRNG->new;
          #or
          $prng = Crypt::PRNG->new($alg);
          #or
          $prng = Crypt::PRNG->new($alg, $seed);

          # $alg  ... algorithm name 'Frotuna' (DEFAULT), 'RC4', 'Sober128' or 'Yarrow'
          # $seed ... will be used as an initial entropy for seeding PRNG

       If $seed is not specified the PRNG is automatically seeded with 32bytes random data taken
       from "/dev/random" (UNIX) or "CryptGenRandom" (Win32)

   add_entropy
         $prng->add_entropy($random_data);
         #or
         $prng->add_entropy();

       If called without parameter it uses 32bytes random data taken from "/dev/random" (UNIX) or
       "CryptGenRandom" (Win32).

       BEWARE: you probably do not need this function at all as the module does automatic seeding
       on initialization as well as reseeding after fork and thread creation.

   bytes
          $octets = $prng->bytes($length);

       See random_bytes

   bytes_hex
          $hex_string = $prng->bytes_hex($length);

       See random_bytes_hex

   bytes_b64
          $base64_string = $prng->bytes_b64($length);

       See random_bytes_b64

   bytes_b64u
          $base64url_string = $prng->bytes_b64u($length);

       See random_bytes_b64u

   string
          $alphanumeric_string = $prng->string($length);
          #or
          $alphanumeric_string = $prng->string;

       See random_string

   string_from
          $string = $prng->string_from($range, $length);

       See random_string_from

   double
          $n = $prng->double;
          #or
          $n = $prng->double($limit);

       See rand

   int32
          $i = $prng->int32;

       See irand

SEE ALSO

       Crypt::PRNG::Fortuna, Crypt::PRNG::RC4, Crypt::PRNG::Sober128, Crypt::PRNG::Yarrow